Django - Celery - SQS - S3 - 接收消息

Question

我有一个 Django 应用程序，我正在使用 Celery、SQS 和 S3。 当我使用 Django、Celery 和 SQS 运行以下函数时，该函数可以正常工作，并且它应该每分钟打印一次“你好”。

from celery.task import periodic_task
from celery.schedules import crontab
@periodic_task(run_every=crontab(hour='*', minute='*', day_of_week="*"))
def print_hello():
    print('hello world')

但该应用还链接到 S3 存储桶。每当一个新文件被保存到S3 a notification is sent to the SQS queue。将通知消息发送到 SQS 队列时会出现此问题。当通知到达队列时，worker 失败。它停止周期性任务 print_hello()，给出以下错误消息：

[2019-11-07 22:10:57,173: CRITICAL/MainProcess] 不可恢复的错误： 错误（'不正确的填充'） ...parserinvoker/lib64/python3.7/base64.py"，第 87 行，在 b64decode 返回 binascii.a2b_base64(s) binascii.Error: 不正确的填充

然后退出。我一直在查看文档，并且整个星期都在尝试排除故障，但没有找到解决方案。我将我的 settings.py 包括在内，以防是配置问题

设置.py

BROKER_URL = "sqs://"
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_RESULT_SERIALIZER = 'json'
CELERY_TASK_SERIALIZER = 'json'
CELERY_DEFAULT_QUEUE = env('CELERY_DEFAULT_QUEUE')
CELERY_RESULT_BACKEND = None 
BROKER_TRANSPORT_OPTIONS = {
    'region': 'us-east-1',
    'polling_interval':20,
    'visibility_timeout': 3600,
    'task_default_queue': env('CELERY_DEFAULT_QUEUE'),
}

Answer 1

celery 期望队列中的 json payload 格式与 SQS 从 s3 接收的格式不同；为了正确处理这些，您可能需要一个单独的定期任务来定期检查这些并排空 s3 通知队列，而不是将 s3 通知发送到 celery 代理队列。 s3 消息正文将显示为described in the amazon documentation here。这是从 S3 发送到 SQS 的示例 2.1 记录：

   "Records":[  
      {  
         "eventVersion":"2.1",
         "eventSource":"aws:s3",
         "awsRegion":"us-west-2",
         "eventTime":The time, in ISO-8601 format, for example, 1970-01-01T00:00:00.000Z, when Amazon S3 finished processing the request,
         "eventName":"event-type",
         "userIdentity":{  
            "principalId":"Amazon-customer-ID-of-the-user-who-caused-the-event"
         },
         "requestParameters":{  
            "sourceIPAddress":"ip-address-where-request-came-from"
         },
         "responseElements":{  
            "x-amz-request-id":"Amazon S3 generated request ID",
            "x-amz-id-2":"Amazon S3 host that processed the request"
         },
         "s3":{  
            "s3SchemaVersion":"1.0",
            "configurationId":"ID found in the bucket notification configuration",
            "bucket":{  
               "name":"bucket-name",
               "ownerIdentity":{  
                  "principalId":"Amazon-customer-ID-of-the-bucket-owner"
               },
               "arn":"bucket-ARN"
            },
            "object":{  
               "key":"object-key",
               "size":object-size,
               "eTag":"object eTag",
               "versionId":"object version if bucket is versioning-enabled, otherwise null",
               "sequencer": "a string representation of a hexadecimal value used to determine event sequence, 
                   only used with PUTs and DELETEs"
            }
         },
         "glacierEventData": {
            "restoreEventData": {
               "lifecycleRestorationExpiryTime": "The time, in ISO-8601 format, for example, 1970-01-01T00:00:00.000Z, of Restore Expiry",
               "lifecycleRestoreStorageClass": "Source storage class for restore"
            }
         }
      }
   ]
}

芹菜消息格式looks like this。